Modification of iodine-lead-methylamine perovskite layer with 1,4-diiodiobenzene
Using 1,4-diiodiobenzene with different concentrations as Lewis base to passivate the defects of lead iodide methylamine(MAPbI3)reduced the defects of calcium titanate layer.The phase and morphology of perovskite films were characterized by X ray diffraction and scanning electron microscopy.The defect density of MAPbI3 was analyzed by fluorescence spectrum and space limited charge current analysis.The electrochemical impedance and J-V curve tests were used.The results showed that compared with the perovskite solar cell without 1,4-diiodibenzene,the defect density decreased significantly after adding 1,4-diiodiobenzene.the open-circuit voltage of the battery increased from 0.83 to 0.95 V,the filling factor increased from 52.5%to 62.3%,and the photoelectric conversion efficiency increased from 6.79%to 8.47%when the molar fraction of 1,4-diiodobenzene in the perovskite layer is 2.1%,and the results remained after multiple repeated experiments.